should warn if List is not imported

[tharvik]

 a = [1]  # type: List[int]

do not give any warning, but

 a = (1,)  # type: Tuple[int]

gives

list.py:1: error: Name 'Tuple' is not defined

[refi64]

Does the latter work if you do a = (1,)?

[tharvik]

@kirbyfan64 ho, typo from my part, that's true, I'm editing my post; but the warning is still there.

[gvanrossum]

This is a duplicate of bug #999. For your program to be correct, both List and Tuple ought to be imported from the typing module.